Data current coupler

ABSTRACT

An improved data coupler assembly provides an improved electromagnet insert having conductive wires positioned within arcuate channels formed along with electromagnet insert. Sealing means to position and seal the conductor wires to the assembly are included. Improved electromagnetic shielding by using metallic plating on the upper member of the coupler assembly provides effective, but lightweight, EMF/RFI protection. A rugged resilient spring means improves the formation of an electromagnet core by biasing the electromagnet insert, and thereby biasing together each electromagnet pair form cores having a minimal air gap. A quick-action panel mounting means secures the coupler assembly to a panel, and improved aligning means precisely secures the upper member of the coupler assembly to the lower member.

This application is a continuation of application Ser. No. 07/576,341filed Aug. 31, 1990, now abandoned.

FIELD OF THE INVENTION

The present invention relates to the field of electrical connectors andmore particularly to noninvasive coupler assemblies and component partsthereof, useful for sensing and transmitting electrical signals fromconductor wires of a twisted pair cable of a data bus.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,904,879 describes a data current coupler/assembly, andmethod of making and assembling the coupler, for receiving signals fromconductor wires of a twisted pair of a data bus and transmitting signalstherealong. The coupler assembly noninvasively couples the data bus tothe conductor wires by using mating pairs of E-shaped electromagnetshaving windings about central legs of the magnets which are electricallyconnected to a control unit to sense and transmit signals along the databus. A lower member, having a cavity to receive conductor wires of thedata bus positioned adjacent to the lower electromagnets, is mounted toa panel. An upper member with upper electromagnets includes a circuitsubstrate having trace windings about substrate apertures, an electronicsubassembly to which the windings are electrically connected to amplifytransmitted and received signals, and a shielded electrical connectorsecured at a connector end connected to circuits of the electronicsubassembly and matable with a connector of a cable extending to thecontrol unit. The upper member is releasable connected to the uppermember via a fastening means and securing means.

U.S. Pat. No. 4,264,827 discloses a method of sensing the transmissionof low-level signal current through an electrical conductor without anelectrical connection to the conductor, using a continuous closed loopconductor wire extending from a current source with coils of theconductor looped around electromagnet coil articles connected toelectronic devices, which arrangement senses changes in theelectromagnetic field established by the current. The arrangement can berepeated at a plurality of locations spaced along the conductor withminimal effect to the signal transmission, and can allow signaling of aplurality of electronic devices in response to the signal currentpassing through the conductor.

Such a current sensing system is desired to be placed aboard aircraftfor use with black boxes and other electronic control units, as isdisclosed in Proposed ARINC Standard 629 presently being considered bythe Airlines Electronic Engineering Committee (AEEC) of AeronauticalRadio, Inc. (ARINC) of Annapolis, Md., and AEEC Letters Nos.87-094/SAI-309, 87-122/SAI-313, and 88-077/SAI-331, which areincorporated herein by reference. Such a system may also be used inother environments where it is desire that a single closed loop data busbe used.

The couplers above provide important advantages in operation andassembly. Nevertheless, none of these couplers uses an improvedelectromagnet structure to provide improved coupler performanceincluding an improved conductive wire positioning within the wirechannels along with electromagnet insert having sealing means toposition and seal the conductor wires to the assembly, improvedelectromagnetic interference ("EMI") shielding using metallic plating onthe upper member rather than a separate shield member, a ruggedelectromagnet biasing means to improve formation of an electromagnetcore, a quick action panel mounting means, and improved aligning meansto secure the upper member to the lower member.

It is desired to devise an improved noninvasive coupler assembly forsensing and transmitting electrical signals from a twisted pair of adata bus, and a method of assembly of such a coupler assembly, whichprovides these important advantages.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide an improvedelectromagnet core for a coupler assembly to minimize the dissipation ofthe strength of signals passing through the data bus system and notinterfere with the integrity of the signals through impedance duringlong term use.

It is a further objective to provide an improved shielding whichprotects the components of a data current coupler from EMI/RFI without aseparate shield member.

It is yet a further objective to provide such a coupler housing whichphysically protects and seals the conductor wires to the couplerassembly over long-term inservice use.

It is another objective to provide a coupler housing which is easy toassemble on a panel, connected to a data bus system, disassembledtherefrom, and removed from the panel.

It is another objective of the invention to provide improved aligningmeans to secure the upper member of the coupler to the lower means.

According to the invention, the coupler assembly includes a lower memberto which is secured an upper member forming an assembly for noninvasivecoupling to a twisted pair of signal conductor wires of a closed loopdata bus to read signals being transmitted therealong by a series ofelectromagnet cores interlaced with loops of the twisted pair. Theelectromagnet cores comprise opposing electromagnets positioned in eachmember and disposed within one or the other of the upper and lowermembers. Opposing end faces of the legs of the electromagnetic magnets,which may be E-shaped, engage each other preferably under slightcompression by a resilient spring means. Portions of the conductor wiresof the twisted pair are placed at a selected location therealong informed arcuate channels extending around the central leg of thepermanent magnets in the lower member, and upon the upper member thenbeing secured to the lower member. The coupler assembly also can eithertransmit and amplify signals therealong by generating an appropriateelectromotive force via an electromagnetic field, and also receive andtherefor verify the signal it transmits.

Embedded within the dielectric material covering the upper member is acircuit substrate, including electrical components and at least aplurality of layers of trace windings about the center legs of theelectromagnets, and electrically connected to the electrical components.In turn, the electrical components are electrically connectable at anelectrical connector of the upper member with a cable assembly whichextends to a corresponding control unit, with the control unit providingelectrical power to the electrical components as well as signal andground connection. The upper member includes shielding formed bymetallic plating on the inner surface of the upper member completelyaround the electronic subassembly and the connections thereof with theconnector interface for EMI/RFI protection, which is then covered by aninsulative covering.

In accordance with one aspect of the present invention, an alignmentmeans is provided to precisely align the upper coupler member with thelower member upon mating. Pivot pins of the lower member at theconnector end of the coupler are disposed within elbow slots of theupper member and pivot therewithin. A projection of the upper membernear the upper electromagnets during pivoting enters a correspondingrecess of the lower member closely corresponding in shape and dimensionthereto and incrementally adjusts the alignment of the upper memberessentially at a single point spaced from the pivot point; theprojection and recess define reference datums of the upper and lowermembers respectively.

Preferably, an electromagnet insert for a data coupler comprises adielectric member defining positions for at least one electromagnet withmating faces exposed in one direction in a planar surface. Theelectromagnet insert includes wire-receiving arcuate channels coursingfrom one side to another side of the member and defining pathways oneach side of a central core of the electromagnet. The arcuate channelsare shaped to match the optimum-shaped loop of a twisted pair cable of adata bus. A sealing lip and side seal extensions are provided to protectthe face of the electromagnet.

Also, a spring member defines a platform such as for resilientlysupporting the electromagnet insert of the data coupler, upwardly withina cavity of the lower coupler member comprising a pair of like springarms formed on a support surface and disposed at opposite ends of aplanar peripheral portion of the support surface to each other. Each ofthe spring arms has an end proximate the base of the opposite springarm. The spring arms extend toward the bases of each other and outwardlyfrom the platform to define a bearing surface disposed to engage abiasing surface of another member such as the lower coupler member. Apair of spring ends arm disposed to extend from the support surface andtogether provide balanced support for the support surface.

Further, the present invention includes a mounting means for mountingthe lower member to another member such as a panel through a simpleprocedure entirely on one side of the panel without separate fasteners.The mounting means has a plurality of pre-determined engaging surfacesformed on the panel such as edge surfaces of spaced apertures or acutout therethrough. The mounting means includes at least one fixedengaging member disposed on the member to engage one of the panel'sengaging surfaces. At least one movable engaging member is also disposedto engage another of the panels engaging surfaces. The movable engagingmember is positioned on a support member operable between a disengagedand any one of a plurality of potential engaged positions whereby themovable engaging member positions both of the engaging members intoengagement in the operable position and disengagement in the inoperableposition.

Embodiments of the invention will now be described with respect to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a data bus system;

FIG. 2 is an isometric view of the coupler assembly of the presentinvention coupled to a pair of conductor wires of the data bus of FIG.1;

FIG. 3A is an exploded top view in perspective of the lower member ofthe coupler assembly of FIG. 2, and FIG. 3B is an exploded bottom viewin isometric of the lower member of coupler of FIG. 2;

FIG. 4 is an exploded top isometric view of the upper member of thecoupler/assembly of FIG. 2;

FIGS. 5A and 5B are top and bottom isometric views respectively of theupper member of FIG. 2;

FIG. 6A is a longitudinal cross-sectional view taken along line 6--6 ofthe upper and lower members of the coupler of FIG. 2 being securedtogether to the conductor wires, and FIG. 6B is a longitudinalcross-sectional view taken along line 6--6 of the upper and lowermembers of FIG. 2 secured together to the conductor wires;

FIGS. 7A and 7B are top and bottom isometric views respectively of a camof the panel mounting means;

FIGS. 8A is a top isometric view of the cam follower of the panelmounting means, FIG. 8B is a top isometric view of the cam follower ofpanel mounting means of FIG. 8A rotated about ninety degrees; and FIG.8C is a bottom isometric view of the cam follower of the panel mountingmeans of FIG. 8A;

FIGS. 9A and 9B are top views of the cam member in the disengaged andengaged panel positions, respectively, and FIGS. 10A and 10B arelongitudinal cross-sectional views taken along lines 10A--10A and10B--10B, respectively of FIGS. 9A and 9B;

FIG. 11A is an isometric vie an electromagnet insert of the lowermember, FIG. 11B is a cross-sectional view taken along line B--B of FIG.11A and FIG. 11C is a cross-section view taken along line C--C of FIG.11A and FIG. 11D an end view of the electromagnetic insert of FIG. 11A;

FIG. 12 is an isometric view of an E-shaped electromagnet;

FIG. 13A is an isometric view of a resilient spring means of the lowermember; FIG. 13B is a top plan view of the resilient spring means ofFIG. 13A; FIG. 13C is a side view of the resilient spring means of FIG.13A; and FIG. 13D is an end view of the resilient spring means of FIG.11A;

FIG. 14A is a top isometric view of a circuit substrate of the uppermember of the coupler having surface mounted electrical components onthe upper surface of the circuit substrate, which is also illustrativeof a bottom isometric view of the circuit substrate having electricalcomponents surface mounted on the bottom of the circuit substrate; and

FIG. 14B is an isometric upper view of one of the internal layers of thecircuit substrate of FIG. 4, showing two of a plurality of traces havinginductance coils for the electromagnets;

FIG. 15 is an illustration of the electromagnets and windingstherearound, coupled to the conductor wires;

FIG. 16A is an isometric view of an alternative embodiment of thepresent invention showing a single electromagnet used for either sendingor receiving signals, and FIG. 16B is an isometric view of analternative embodiment of an electromagnet insert used for eithersending or receiving signals; and

FIG. 17 is an alterative embodiment of a resilient spring means for thelower member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a representation of the data bus system 20 to which thepresent invention is relevant. A twisted pair cable 22 of conductorwires 22A,22B extends between end terminations 24,26 and comprises aclosed loop, and a plurality of loops 28 occur at selected spacing, eachloop 28 having a length and shape selected to minimize impedance effectsand signal reflection. At selected ones of otherwise closed loops 28 aremounted coupler assemblies 30 each having a width preferably less than aloop length to minimize distorting the desired length and shape of anopen loop, thereby avoiding impedance effects and signal reflection.

Stub cables 32 extend from the respective coupler assemblies 30 torespective control units 34, such as black boxes, providing electricalconnections therebetween. Each control unit 34 preferably has a SerialInterface Module (not shown) for modifying digital signals fromManchester Encoded Signals into doublet signals to be transmitted alongthe data bus system 20, and correspondingly for translating such encodedsignals into digital signals for integrated circuits within the controlunit. Each control unit 34 will also provide power for the amplifiers inthe coupler assembly 30 to boost received and transmitted signals.

FIG. 2 illustrates the coupler assembly 30 of the present inventioncoupled to the twisted pair cable 22 of conductor wires 22A,22B of adata bus system 20 such as that of FIG. 1 and as disclosed in U.S. Pat.Nos. 4,904,879 and 4,264,827, and the AEEC Letters referred to herein.Coupler assembly 30 is noninvasively affixed at a selected locationtherealong at a loop 28 of the twisted pair cable 22, slightly openingthe loop which would otherwise be closed along cable 22. Couplerassembly 30 comprises an upper member 36 and a lower member 38, with thelower member 38 including a base 40 mounted to a panel 42 by a panelmounting means 44 (not shown).

FIGS. 3A, 3B, 4, 5A and 5B show in greater detail the upper and lowermembers 36,38, and FIGS. 6A and 6B illustrate their assembly together.FIGS. 3A and 3B illustrate components of lower member 38 of couplerassembly 30, including base 40, resilient spring means 50, anelectromagnet insert or wire holding member 52 having electromagnets54A, 54B, a cam 56, and a cam follower 58.

As shown in FIGS. 3A and 3B, lower member 38 includes a base 40 moldedof dielectric plastic material, such as nylon, or a liquid crystalpolymer ("LCP"). The base 40 includes an aligning recess 60 havingaligning surfaces 62 to receive the upper member aligning means such asprojection 66, pivot pins 68 positioned at one end 78, or "pivot end" ofbase 40, an electromagnet insert-receiving cavity 70, and acam-receiving cavity 72 having a cam follower guide path 74. The end 76of base 40 opposite the pivot pins 68 or "coupling end", includes afastener-receiving cavity 80 and fixed engaging members 82, such as"elephant" feet 82', extending in a downwardly direction.

As illustrated in FIGS. 6A and 6B, for precision alignment of upper andlower members of data coupler, base 40 of lower member 38 has a taperedaligning surface 62 formed on aligning recess 60, which engagesprojection 66 of upper member 36 located adjacent the first and secondelectromagnets near coupling end 76. Both projection 66 and aligningrecess 60 are molded to precise corresponding shapes and dimensions, andin each of the upper and lower members all other features moldedthereinto are measured from the location of the centerlines of theprojection and recess which comprise respective reference datums for themolded parts. The projection 66, coupled with pivot pins 68 formed onbase 40 of lower member 38 which fit within an elbow slot 84 of uppermember 36, provides means to precisely align upper member 36 to lowermember 38. This in turn precisely positions electromagnets 54A,54B oflower member 38 to electromagnets 86A,86B positioned in upper member 36.Projection 66 and recess 60 are adapted to engage and incrementallyadjust the position of upper member 36 with respect to lower member 38upon initial entry of said projection into said aperture untilprojection 66 is coaxial with aperture 60, thus providing alignment ofupper and lower members 36,38 determined by means integral therewith andessentially at a single point substantially spaced from the pivot point.

As shown in FIGS. 3A, 3B, 7A, 7B, 8A, 8B and 8C, the panel mountingmeans 44 comprise "quick action" cam 56 which activates cam follower 58having a movable engaging member 88, such as an "elephant" foot 88', tograsp panel 42. The cam follower 58 has side engaging surfaces 90 andshoulder engaging surfaces 94 which fit into and are guided by verticaland horizontal surfaces 92,96 of cam follower guide path 74 formed inlower member 38.

As shown in FIGS. 3B and 7B, cam 56 has a cylindrical base 100 whichfits into cam-receiving cavity 72 formed within base 40 of lower member38. The cam-receiving cavity 72 includes a lower opening 102, whichreceives cylindrical base 100 of the cam 56. A "C"-shaped retention ring104 secures cam 56 via a groove 106 formed on cylindrical base 100 tobase 40. A spring washer 108 spaced between "C"-shaped retention ring104 and lower surface 110 of base 40 allows cam 56 a degree of verticalmovement along the major axis 112 of cylindrical base 100. A handle 114is formed on top of cam 56 for turning cam 56 between engaged anddisengaged positions. While a counterclockwise cam movement forengagement of cam follower 58 to panel 42 is illustrated in FIG. 7B, aclockwise cam movement may also be used for initial engagement with thereverse movement providing the movement for disengagement.

As shown in FIGS. 9A, 9B, 10A and 10B, a plurality of predeterminedengagement surfaces 120, such as side walls formed by openings 122, areformed on panel 42. The fixed engaging members 82, such as elephant feet82', at first fit loosely within associated openings 122 defining theengagement surfaces 120, and movable engaging member 88, such aselephant foot 88', at first fits loosely within opening 122 havingengaging surface 120 and then is firmly engaged upon appropriaterotation of cam 38.

As shown in FIGS. 8A, 8B, 8C, and 10A and 10B cam follower 58 definingmovable engaging member 88 has a projection 124 which fits within a camslot 126, which defines a cam actuating surface 128 when rotated. Themating of projection 124 to cam slot 126 assures that cam follower 58tracks the position of cam 56. As shown in FIGS. 5A, 5B, 6A and 6B, cam56 via cam slot 126 and surface 128 engages the surface of projection124 of cam follower 58 which forces engaging arm 88 in the properengagement with engagement surface 120 of panel 42. Cam 56 applies theprecise pressure setting to the engaging surfaces 120 via the movableengaging member 88 by movement of the cam handle 114 in acounter-clockwise direction to engage a plurality of engaging surfacesor base teeth 130, formed in cam-receiving cavity 72 of lower member 38.Cam 56 may be moved in a vertical direction along major axis 112 bycompressing the spring washer 108, so that a plurality of correspondingengaging surfaces or cam teeth 132 formed on lower surface 134 of cam 56can engage and disengage base teeth 130 of lower member 38 as cam 56 isrotated. Each engaging member 82,88 includes a locking surface 140,which engages the engaging surface 120 of panel 42, defined by a taperedsurface which biases lower member 38 against panel 42 as cam 56 actuatesthe movable engaging member 88 and fixed engaging member 82 intoengagement with engagement surfaces 120 of panel 42.

As shown in FIG. 6B, when upper member 36 is secured over lower member38, lower surface 142 of upper member 36 bears against cam handle 114and locks cam handle 114 so that engaging members 82,88 are ruggedlysecured in engagement with engagement surfaces 120 of panel 42. Thus,cam teeth 130 remain in engagement contact with base teeth 130. Thisprevents cam 56 from moving in a vertical direction, compressing springwasher 108 and disengaging cam teeth 132 of cam 56 from base teeth 130of lower member 38. This provides a rugged panel-mounting means 44 towithstand vibrations, temperature and pressure changes, and cycling, yetprovides quick action connection and disconnection from panel 42. It isshown in FIGS. 6A and 6B that panel 42 may be gently arcuate as iscommon in aircraft, and that by reason of engaging surfaces 140 beingtapered it is understandable that firm engagement is generated withcorresponding panel engaging surfaces 122 of varying thicknesses withina limited range, and that the panel engaging surfaces may be opposingedges of a single cutout rather than discrete apertures. It is alsoshown in FIGS. 6A and 6B that panel 42 may be slightly nonplanar, suchas being gently arcuate as is common in aircraft, and that by reason ofengaging surfaces 140 being tapered and thus providing a limited rangeof corner engaging positions, firm engagement can be generated, usingcam 56, of engaging surfaces 140 with corresponding panel engagingsurfaces 120 of panels of varying thicknesses within a limited range,and that the panel engaging surfaces amy be opposing edges of a singleaperture through the panel (or panel cutout) rather than discreteapertures.

Turning now to FIGS. 4, 5A, and 5B, upper member 36 comprises a top bodymember 150, a circuit substrate 152 having a plurality of surfacemounted electrical components 154 connected to an electrical receptacleconnector 156, the electromagnets 86A,86B, and a bottom body member 158.

As shown in FIGS. 6A and 6B, upper member 36 is fastened to lower member38 about conductor wires 22A,22B at a coupling section 160 by fastenermeans 162 and at a connector section 164 by pivot pins 68 in lowermember 38 held by and rotatable within an elbow slot 84 having arcuatebearing surfaces 166 in upper member 36. Pivot pins 68 extend betweenflanges of lower member 38 whereby they are substantially physicalprotected by portions of the lower member against inadvertent contactand damage during handling prior to assembly to upper member 36, andelbow slots extend transversely to communicate with side surfaces ofupper member 36 along the vertical and horizontal slot portions toaccommodate the flanges of lower member 38. Connector section 164includes an electrical receptacle connector 156, having a plurality ofterminals 170 matable with a plug connector (not shown) terminating theend of a stub cable 32 of FIG. 1 connected to a control unit or blackbox 34.

A square shouldered flange 172 fits into a square flange receivingcavity 176 formed within top and bottom body members 150,158 whichallows fastening of a pair of spaced horizontal flanges 178 ofelectrical receptacle connector 156 to upper member 36 using screws 168,for example. In this manner, electrical receptacle connector 156 issecured to top and bottom body members 150,158 together upon theirmating together to enclose the circuit substrate.

As shown in FIGS. 11A, 11B, 11C and 11D, the electromagnet insert 52comprises an insert body 174, and the pair of electromagnetic magnets54A,54B, each having a central leg 180 and outer legs 182 extending fromtransverse portion 184. One electromagnet 54A is used for receivingsignals and the other electromagnet 54B is used for sending signals. Asshown in FIG. 12, "E"-shaped electromagnets are preferably used.Electromagnets 54A,54B are preformed ferrite cores, which are embeddedin insert body 174 formed of elastomeric material, such as siliconrubber, in a manner that secures the electromagnets 54A,54B.Electromagnets 54A,54B may be of the type sold by Ferroxcube Division ofAmperex Electronic Corporation of Sangerties, N.Y., which are made fromconventional material, such as linear ferrite, a ceramic filled withferrous particles. Faces 186,188 are preferably smooth and preciselycoplanar, with a variation in the height of legs 180,182 from 0.2 to 0.5mils.

As shown in FIGS. 5B, 6B, the faces 186,188 of the central and outerlegs 180,182 are exposed to engage with corresponding exposed faces192,194 of central and outer legs 196,198 respectively, of correspondingE-shaped magnets 86A,86B formed on a transverse portion 200, which issecured within upper member 36 upon assembly. The exposed faces186,188,192,194 may be covered with paper, plastic film or grease orother suitable covering to prevent oxidation of faces 186,188 ofelectromagnets 54A,54B prior to complete coupler assembly, and isremoved at assembly.

As shown in FIGS. 11A, 11B, 11C and 11D, insert body 174 includes a pairof gently arcuate channels 210A,210B across upper surface 212 from firstchannel ends 214A,214B at first side 216 to second channel ends218A,218B at second side 220 and between legs 180,182 of electromagnets54A,54B. The arcuate channels 210A,210B generally take configuration ofloop 28 of the twisted pair cable 22 and form a convex path away fromeach other which encloses central legs 180 of electromagnets 54A,54B.The slope of channel bottom 230 may be gradual as shown in FIG. 11B.Alternatively, arcuate channels 210A,210B may be shaped in a verticalprofile where the entire vertical rise of arcuate channels 210A,210B isdefined to occur outwardly from the passage of arcuate channels210A,210B past central legs 180 of electromagnets 54A,54B. In thismanner, arcuate channels 210A,210B position loop 28 of twisted paircable 22 in an essentially horizontal run past central legs 180 ofelectromagnets 54A,54B, which could provide for greater sensitivity toreceiving or transmitting signals.

Preferably, electromagnets 54A,54B may be shaped to contour and shape ofthe arcuate channels 210A,210B in order to provide maximumelectromagnetic sensitivity. For example, as shown in FIG. 12, thecenter leg 180 may include a taper 208 to allow arcuate channels210A,210B to position the twisted pair cable 22 in very close proximityto the central leg 180 of electromagnets 54A,54B. As shown in FIG. 11C,arcuate channels 210A,210B are constructed to have a relatively thinelectromagnet insert wall 204 adjacent to the central leg 180 of theelectromagnet or central leg wall 204, as compared to the electromagnetinsert wall 206 adjacent outer leg 182 or outer leg wall 206. Typically,insert body 174 has a wall spacing of 0.025 inches between arcuatechannels 210A,210B and central leg 180.

Conductor wires 22A,22B will be received and held along bottom 230 ofarcuate channel 210A,210B because the distance between arcuate channelwalls 222,224 is less than the diameter of conductor wires 22A,22B atleast near the channel ends. This assures that conductor wires 22A,22Bwill be rigidly secured along arcuate channels 210A,210B between outerlegs 182 and central leg 180 of each of electromagnets 54A,54B uponassembly.

As pointed out above, in order to assist in the proper positioning ofconductor wires 22A,22B in arcuate channels 210A,210B, the particularthree-dimensional shape of arcuate channels 210A,210B is enhanced by thetaper 208 formed on center leg 180 of the E-shaped electromagnets54A,54B. This holds conductor wires 22A,22B in the shape of loop 28 ofthe twisted pair cable, which reduces impedance and minimizesreflectivity of signal transmission along the wires.

As shown in FIG. 3A, electromagnet insert 52 is received into andsecured within electromagnet insert receiving cavity 70, preferablyunder interference fit. As shown in FIGS. 11A, 11B, 11C, upper surface212 of insert body 174 includes a sealing lip 228, such as an "O" shapedlip 228', formed about its periphery, and a pair of side seal extensions232 to seal around first channel ends 214A,214B and second channel ends218A,218B of arcuate channels 210A,210B. The side seal extensions 232deform around conductor wires 22A,22B when upper member 36 is joined tolower member 38, such as shown in FIG. 6B.

As shown in FIG. 3A, upon assembly of insert body 174 into electromagnetinsert receiving cavity 70, first and second slots 234,236 define cableexits at the top of electromagnet insert receiving cavity 70 and receiveextensions of the insert containing first channel ends 214A,214B andsecond channel ends 218A,218B respectively so that both conductor wires22A,22B are received together through first slot 234, then intorespective first channel ends 214A,214B, along the arcuate channels210A,210B to second channel ends 218A,218B and together through secondslot 236.

The electromagnet insert-receiving cavity 70 includes a support ledge242 to receive spring arms 244 for the resilient spring means 50, aplurality of holes 246 therethrough for the venting of air uponinsertion of electromagnet insert 52 into electromagnet insert receivingcavity 70 under interference fit, and a vertical support rib 248.Vertical support rib 248 is located between electromagnets 54A and 54Band includes posts extending upwardly between opposing outer legs 182and opposing central legs 180 of the electromagnets, with rib 248 andits posts extending into corresponding recesses into the bottom surfaceof the elastomeric material forming insert body 174 of electromagnetinsert 52, as seen in FIG. 3B, and thus tend to rigidify insert body 174between the pairs of legs of the lower member electromagnets 54A,54B forstabilizing each electromagnet against strain applied by twisted paircable 22. The electromagnet insert 52 has at least one resilient springmeans 50, and preferably a pair of resilient spring means 50 forindependent spring biasing of electromagnets 54A,54B, to permit insertbody 174 to sustain further compression when urged downwardly by theassembly of upper member 36 to lower member 38.

Referring to FIGS. 6A, 6B and 13A-13D, the resilient spring means 50 isprovided to keep lower member electromagnets 54A,54B closely adjacentto, and in contact with, upper member electromagnets 86A,86B to minimizethe air gap, which enhances transfer of energy. The resilient springmeans 50 comprises a unitary member having a pair of spring arms 244formed in a juxtaposed "X" configuration from a planar peripheralportion of a support surface 250, which engage support ledge 242 ofelectromagnet insert receiving cavity 70. The spring arms 244 are alikeand extend from respective bases proximate opposite ends of support orbiasing surface 250 and toward the bases of each other along andproximate respective sides of the peripheral portion; spring arms 244extend downwardly to form the juxtaposed "X" configuration, and aretapered towards free ends 252 of spring arms 244 engaging support ledge242. The ends 252 of spring arms 244 are slightly bent upwardly to forma smooth bearing surface 260 to engage support ledge 242. A suitablematerial to construct the resilient spring means is stainless steel, orother materials including plastics having suitable springcharacteristics.

Two sides 254 of resilient spring means 50 extend from each end 256 ofsupport surface 250 and have outwardly extending locking tabs 258. Theselocking tabs 258 engage downwardly facing ledges along side walls 262(FIGS. 6A and 6B) of electromagnet insert receiving cavity 70 to secureresilient spring means 50 within electromagnet insert receiving cavity70.

As shown in FIGS. 13A and 13B, tapered spring arms 244 of resilientspring means 50 provide a maximum degree of structural material at thepoint of spring action which assures reliable spring action duringintense vibrations, temperature and pressure cycling and other stresses.This assures continued engagement between upper and lower memberelectromagnets 54A,54B,86A,86B to form an electromagnet core 264, asshown in FIG. 6B, which has essentially no air gap. After electromagnetinsert 52 is secured within electromagnet insert receiving cavity 70,the end faces 186,188 of the electromagnet central and outer legs180,182 may be covered with a protective paper, grease or the like whichwill be removed just prior to placement of conductor wires 22A,22B intoarcuate channels 210A,210B.

As illustrated in FIG. 6A, upper surface 226 of electromagnet insert 52is preferably raised slightly above the top of electromagnetinsert-receiving cavity 70 prior to complete assembly of couplerassembly 30 via upper member 36; lower member 38 is shown mounted topanel 42 by panel-mounting means 44, and conductor wires 22A,22B are inplace in arcuate channels 210A,210B of electromagnet insert 52.

Referring now to FIG. 4, upper member 36 comprises top body member 150,bottom body member 158, circuit substrate 152, electrical components 154preferably surface mounted on the upper and lower surface of circuitsubstrate 152, electrical receptacle connector 156 which interconnectscircuit substrate 152 to stub cables 32 and control units 34, and thepair of "E"-shaped electromagnets 86A,86B. A suitable material forforming the top and bottom body members is a liquid crystal polymer("LCP"), which can be plated with metallic materials, and may be VECTRAC-810 or alternatively may be VECTRA A-130 (trademark of CelaneseCorporation). The electromagnets 86A,86B are constructed of preformedferrite cores, similar to lower member electromagnets 54A,54B.

The electrical receptacle connector 156 includes a dielectric housing266 containing the plurality of terminals 170, and a metal shell 270secured around housing 266. The square flange 172 fits within squareflange receiving cavity 176, which by its square shape enableselectrical receptacle connector 156 to be secured to upper member 36,when top and bottom body members 150,158 are joined together around thecircuit substrate to form upper member 36. Generally, electricalreceptacle connector 156 may be a conventional type, such as one meetingMilitary Specification 26500, or other suitable electrical receptacleconnector.

The electromagnets 86A,86B each include central leg 196, having the sametaper 208 of central leg 180 of electromagnets 54A,54B, and two outerlegs 198 extending from the transverse portion 200. The coupling end 76of circuit substrate 152 includes central and outer leg-receivingapertures 272,274 to receive central leg 196 and outer legs 198,respectively of electromagnets 86A,86B therethrough. Screws 284 securecircuit substrate 152 to top body member 150, with electromagnets86A,86B secured therebetween.

As shown in FIGS. 4, 6A and 6B, electromagnetic shielding to provideelectromagnetic interference ("EMI") or radio frequency interference("RFI") protection of the electrical components 154 is accomplished byplating the top and bottom body members 150,158 of upper member 36. Theplating 280 on top and bottom upper body members 150,158, along witheither conductive adhesive or electromagnetic taping of all seamsbetween the plating 280 of the top and bottom upper body members150,158, provides a continuous three-dimensional shield surrounding theelectronic package for EMI/RFI protection.

As shown in FIG. 6A, top body member 150 includes a cavity 276 formedabove circuit substrate 152 and having enough depth to receive thereintocircuit substrate 152 and the coextending planar and slightly narrowerportion of bottom body member 158 so that the top and bottom bodymembers are spaced from and fit around the electrical components 154surface mounted on the top and the bottom of the circuit substrate 152.The bottom body member 158 includes a seal-engagement surface 268 formedon the lower surface such that upper member 36 receives sealing lip 228of electromagnet insert 52.

Plating 280 to shield EMI/RFI is positioned on all exposed surfaces oftop and bottom body members 150,158, and members 150,158 are molded withgenerous radii at all corners to facilitate adherence of the platingmaterial thereto. Also, it is preferred that the exposed surfaces definea microscopically irregular surface to enhance plating materialadherence which may be accomplish with molds which have been sandblastedto a textured surface. Slots 282 joining the leg-receiving apertures ofbottom body member 158 define plating gaps 282, which disallowconductive engagement of the plating 280 around electromagnets 86A,86B.The plating gaps 282 prevent a conductive path from being formed by acontinuous winding around the legs 196,198 of electromagnets 86A,86B,which minimizes any unwanted coils and inductance generation by theplating 280 and interference with transmit or receive signals.Typically, plating 280 comprises an electrolessly plated coating ofcopper followed by thin coating of nickel electroplated thereonto, whichforms a layer of plating from 0.250 mils to 0.600 mils in thickness; theratio of the copper thickness to that of the nickel may be about 5:1.

For best EMI/RFI protection, all seams between the top and bottom bodymembers 150,158 are filled with conductive adhesive when the top andbottom body members 150,158 are joined together by the adhesive materialperipherally therearound and by screws 286 at the pivot end 78 to forman integral upper member 36.

As illustrated in FIG. 14A, circuit substrate 152 includescircuit-bearing members 304 to which are secured by surface-mounting aplurality of electrical components 154 such as capacitors, resistors,transistors, diodes, and so on, defining amplifier circuits appropriatefor signal amplification.

Power is provided to coupler assembly 30 by control unit 34 throughelectrical receptacle connector 156 of upper member 36, and chassisgrounding is also provided thereby. Signals received from the data busare amplified for transmission to control unit 34. Signals are alsoreceived from control unit 34 and are amplified to be sent along thedata bus system 20.

Transmitted signals are preferably of the doublet type, encoded as suchwithin control unit 34 of FIG. 1 such as by means of a Serial InterfaceModule. The electronic components may also have appropriate circuits toprovide coupler assembly 30 with redundant receiving and transmittingcapability.

FIG. 14B shows one of a plurality of layers 310 which may comprisecircuit substrate 152. The typical layer 310 includes a plurality ofconductive pads 312 which engage electrical circuity 316, such as tracecircuit paths 318 comprising the inductance coil windings 320. Forexample, heat-resistant thermoplastic film or glass fibers embedded inepoxy to isolate the circuitry on their facing surfaces may be used. Thetrace circuit paths of layers 310 are disposed on respective uppersurface 322 and lower surface 324, which will be interior surfaces oflayers 310, and together upon assembly will define inductance coils326A,326B about central apertures 328A,328B respectively. The number oflayers 310 is dependent on particular characteristics of the electricalsignals to be transmitted and received. For example, six layers of tracewindings will provide for sufficient inductance coils 326A,326B for mostapplications. Further, details of other suitable circuit substrates 152,and the construction of trace circuit paths 318, are described in U.S.Pat. No. 4,904,879, cited above.

As shown in FIG. 4, electromagnets 86A,86B are inserted into circuitsubstrate 152, with an optional resilient member 290 positioned aboveelectromagnets 86A,86B. The top body member 150 receives transverseportions 200 of electromagnets 86A,86B. After the insertion ofelectromagnets 86A,86B, the resilient member 290, if used, is placedwithin a recess 300 above transverse portions 200 of electromagnets86A,86B securing them within top body member 150. This fills anyincremental spaces between the traverse portions 200 of theelectromagnets 86A,86B and the top wall 302 of the recess 300.

The end faces 192,194 of central leg 196 and outer legs 198,respectively, preferably extend incrementally outwardly below the bottomsurface of circuit substrate 152. After assembly of electromagnets86A,86B into upper member 36 a protective cover, such as a piece ofpaper, plastic film or grease, for example, may be removably securedover end faces 192,194 until final coupling of upper and lower members36,38, at which time protective cover is removed.

FIGS. 6A and 6B illustrate how upper and lower members 36,38 are finallysecured together about conductor wires 22A,22B. A screw 340 of afastener means 342 has been inserted into a profiled aperture 344through an end flange 346. A hole portion 348 is dimensioned to beslightly larger than a shaft portion 350 to allow rotation. A "C"-shapedretention ring 352 secures within a groove 354 to hold screw 340 inaperture 344. If needed, protective covers or the like are removed fromthe faces 186,188,192,194 of electromagnets 86A,86B. Pivot pins 68 areplaced in position into elbow slots 84, and upper member 36 is thenpivoted so that electromagnets 86A,86B are moved toward electromagnets54A,54B of lower member 38.

A locking end 356 of screw 340 enters a socket section 358 of a socket362. During pivoting, the upper member aligning means 64, such asprojection 66, on upper member 36 enters aligning recess 60 and engagesaligning surfaces 62 of lower member 38. Preferably, the lowermostportions of projection 66 are tapered or chamfered to comprise lead-insfacilitating alignment of upper member 36 with lower member 38. Thearcuate bearing surfaces 166 of elbow slots 84 of upper member 36coupled with the upper member aligning means 64 assure proper engagementwith lower member 38 prior to being secured together.

Referring to FIGS. 6A and 6B, fastener means 342 can be one-quarter-turnfasteners of the type sold by Southco, Inc. of Lester, Pa. under PartNos. 82-11-240-16, 82-32-101-20, and 82-99-205-15. It is preferred thatthe fastener be spring biased after turning to maintain the coupling endof the upper and lower coupler members firmly together to maintainassured mechanical engagement of the mating faces of the electromagnets,and this may easily be accomplished by a curved washer under the head ofthe fastener 340 with a flat washer between the curved washer and theplated plastic to protect the upper coupler member against wear, all asis conventional.

Screw 340 is adapted to be rotated by a screwdriver to lockingly engagethe socket 362. The locking end 356 includes a pair of wing tabs 364received along channels (not shown) formed at the top of socket section358, whereafter upon appropriate rotation of screw 340 by a tool, wingtabs 364 override and latch behind stop surfaces defined by inwardbosses (not shown) formed in the top portion of socket section 358. Thesocket 362 includes a knurled enlarged head 368, which is held firmlywithin profiled aperture 344 after being force fit thereinto. Thefastener means 342 permits disassembly if desired, and other suitablefastening mechanisms can optionally be used. The electromagnet insert52, which is slightly raised above the top surface of lower member 38,is urged further into electromagnet insert-receiving cavity 70 of lowermember 38 and biased against resilient spring means 50 when upper member36 is locked into place by screw 340 being rotated through a 90 degreeturn, thereby rotating the wing tabs 364 into locking position behindand beneath corresponding bosses (not shown) of socket 362. Theresilient spring means 50 via spring arms 244 becomes slightlycompressed against the support ledge 242 and applies continuous slightbias of electromagnet faces 186,192 and 188,194 against each other afterassembly.

As illustrated in FIG. 15, electromagnet faces 192,194 engagecorresponding electromagnet faces 186,188 to complete the formation oftwo electromagnet cores 370A,370B about conductor wires 22A,22B. A firstcore 370A comprising electromagnets 54A,86A is a receiving core, and asecond core 370B comprising electromagnets 54B,86B is a transmittingcore.

There are modifications and variations which may be made to thepreferred embodiment described herein. For example, various types ofelectromagnets may be used to form the electromagnet cores suitable foruse with the coupler assembly 30. For example, other electromagnetssuitable for use with the data coupler 30 include those forming a"C"-core, "H"-core, and pot cores. Further, a single coupler assembly 30may include only the single receiving core 370A, or the singletransmitting core 370B.

As shown in FIG. 16A, an electromagnet 378 forming a single pot corewould provide an ideal shape to receive a single loop 28 of a twistedpair cable 22 for either transmitting or receiving signals. As shown inFIG. 16A and 16B, electromagnet 378 for a single pot core includes acentral leg 380 and two outer legs 382, which fit within an insert body384 having a pair of arcuate channels 386A,386B. Further, central leg380 may be shaped in an elliptical cross section to better fit within aloop 28 of twisted pair cable 22 and minimize the formation of unwantedimpedance. Alternately, a pair of electromagnets 378, positioned into asingle coupler assembly 30, can be arranged side-by-side on adjacent ornon-adjacent loops 28 for receiving and transmitting signals fromtwisted pair cable 22.

In yet in another variation, the electromagnet insert 52 may be dividedinto two parts, one for the receiving electromagnet 54A and one thetransmitting electromagnet 54B. While this embodiment of electromagnetinsert 52 (shown by line Z--Z in FIG. 11A) may be used for bothreceiving and transmitting cores 370A,370B, it is also apparent that onepart of the divided electromagnet insert 52 holding an "E" shapedelectromagnet 54A may also be used to hold a single receiving ortransmitting electromagnet 54A,54B.

In another variation, spring arms 244 may, in addition to forming thejuxtaposed "X" configuration, comprise either a juxtaposed "W" or "V"configuration. The selection of a particular configuration, either "W","V" or "X" which have decreasing spring rigidity, respectively, woulddepend on the degree of needed spring action and required stiffness.

As shown in FIG. 17, resilient spring means 50 may comprise a pluralityof coil springs 392 disposed between a support member 394 underelectromagnet insert 52. The support member 394 has a plurality ofprojections 396 which lock the coil springs 392 into position on eachside of support member 394.

In another variation, dielectric potting compound, such as epoxy resin,may be injected within upper and lower cavities 276,278 to embed andseal the electronic components 154. The potting material is desirable tobe resistant to thermal shock and to have a low coefficient of thermalexpansion to minimize stressing on electrical components 154 uponelevated temperatures, and also be compatible with the coefficients ofcircuit substrate 152. One such potting material is 4215 epoxy resinsold by Dexter Hysol Company of Olean, N.Y.

In yet another variation, guide surfaces 92 of lower member 38 maydirect the movable engaging member 88 in other than directions away fromfixed engaging member 82. This is accomplished by positioning cam 56 tomove cam follower 58 along the redirected guide surfaces 92, such as onewhich directs the movable engaging member 88 toward fixed engagingmember 82.

Upper and lower members 36,38, respectively, may preferably be placed incontainers such as plastic blister packages for their protection priorto installation.

The embodiments above provide a number of significant advantages. Thecoupler assembly 30 includes a quick action panel-mounting means 44which quickly and accurately positions coupler assembly 30 onto a panel42. In a like manner, the coupler may be quickly removed from panel 42replacement.

In another advantage, electromagnets 54A,54B,86A,86B conform to theshape of loop 28 of twisted pair cable 22 via arcuate wire channels210A,210B formed within electromagnetic insert 52 along with the shapeof the center legs of the electromagnets. This reduces impedance andminimizes reflectivity of signal receptions and transmissions alongconductive wires 22A,22B. The shapes of arcuate channels 210A,210Bposition conductor wires 22A,22B closer to center leg 180 ofelectromagnets 54A,54B than outer legs 182, which also improves signaltransmission and reception.

As yet another advantage, a rugged resilient spring means 50 ispositioned in electromagnetic insert-receiving cavity 70 to assurebiased engagement of the upper and lower electromagnets 54A,54B,86A,86B.This minimizes any air gap between the interfaces of electromagnet cores370A,370B and provides a rugged construction to maintain core engagementduring temperature cycles, vibrations, and pressure cycles. The sealinglip 228 of electromagnet insert 52 together with the side sealextensions 232 assure an intact engagement to control moisture betweenthe pairs of electromagnets 54A,54B,86A,86B together to form theelectromagnetic inducting cores 370A,370B.

As yet another advantage, EMI/RFI protection is provided by the plating280 formed by direct metallic coating onto the top and bottom upper bodymembers 150,158. This plating, preferably of nickel and coppermaterials, reduces the weight and complexity of the coupler assembly 30,yet provides adequate EMI/RFI protection

Of course, it should be understood that a wide range of changes andmodifications can be made to the preferred embodiment described above.It is therefore intended that the foregoing detailed description beregarded as illustrative rather than limiting, and that it be understoodthat is the following claims, including all equivalents, which areintended to define the scope of this invention.

We claim:
 1. A coupler assembly for coupling to a data bus system havinga twisted pair cable of signal conductor wires in a closed bus loop,comprising:at least one electromagnet core, each core defined by a pairof first and second electromagnets each having a central leg and twoouter legs having mating end faces forming closed electromagnetic loopsabout each said signal conductor wire upon mating, said central legs ofsaid first and second electromagnets extending through an open loop ofsaid conductor twisted pair cable; a lower dielectric member containingeach said first electromagnet within a dielectric body of anelectromagnet insert exposing said mating end faces of said legs of eachsaid first electromagnet along an upwardly facing mating face, saidinsert having signal conductor wire-receiving arcuate channels definedthereinto coursing from a first side to a second side of said lowermember and between said central leg and outer legs of each said firstelectromagnet, said arcuate channels conforming to the shape of saidopen loop of said twisted pair cable of said data bus, and said lowermember including a first fastener means at said coupling end and a firstsecuring means at a pivot end opposed from said coupling end; and anupper member comprising a circuit substrate, a top body member and abottom body member formed around said circuit substrate and within whicheach said second electromagnet is disposed at said coupling end thereof,said circuit substrate having electrical components and being positionedwithin a closed cavity defined within said top and bottom body membersrespectively, said upper member including a second fastener means atsaid coupling end adapted to cooperate with said first fastener means tofasten said upper and lower members together at final assembly, and saidupper member further including a second securing means at said pivot endopposed from said coupling end adapted to cooperate with said firstsecuring means to secure said upper and lower members together at finalassembly; said upper member including an electrical connector at saidpivot end electrically connected to said electrical components of saidcircuit substrate disposed to receive or transmit signals and having amating interface adapted to be electrically connected to a control unit,said circuit substrate inductively coupled to each said secondelectromagnet; said upper member having shielding means formed byplating of surfaces of said top and bottom body members surrounding saidcircuit substrate, said bottom body member having plating gapsdisrupting the periphery of apertures through which extend said centralleg of each said second electromagnet to prevent the formation of ametallic loop therearound, and said upper member positioning andexposing said mating end faces of said legs of each said secondelectromagnet along a downwardly facing mating face; and said upper andlower members adapted to be assembled and fastened together such thatsaid mating electromagnet end faces engage each other forming said atleast one electromagnet core about said conductor wires disposed alongand within said arcuate channels prior to fastening whereby signalseither in transmission along said data bus are sensed by windings of asaid electromagnet core and amplified by said coupler assembly andtransmitted to said control unit, or signals desired to be sent alongthe data bus by said control unit are amplified by said coupler assemblyand sent by a said electromagnet core.
 2. A coupler assembly as setforth in claim 1 wherein said lower member includes resilient springmeans positioned to bias each said first electromagnet upwardly so thatlegs thereof extend slightly above said upwardly facing surface of thelower member for the mating end faces thereof to be engaged by matingfaces of said second electromagnet legs, and each said firstelectromagnet to be urged incrementally downwardly during mating againstsaid resilient spring means, thereby establishing slight compressiveforce urging the mating end faces against each other thereafter.
 3. Acoupler assembly as set forth in claim 1 wherein said arcuate channelsdefine in the vertical direction a generally horizontal run past saidcentral leg of each said first electromagnet thereby minimizingimpedance and signal reflection when the conductor wires are positionedtherein and therealong.
 4. A coupler assembly as set forth in claim 1wherein each said first electromagnet is embedded within elastomericmaterial defining an electromagnet insert shaped to be received within acorresponding electromagnet insert-receiving cavity in said coupling endof said lower member, said elastomeric material exposing said mating endfaces of said first electromagnet legs, and including a sealing lip andside seal extensions to seal the engagement of the first and secondelectromagnets of each said pair, said elastomeric material includingdefined thereacross said wire-receiving channels alignable withcorresponding wire-receiving slots in side walls of saidinsert-receiving cavity.
 5. A coupler assembly as set forth in claim 1wherein said first and second fastener means together comprise afastener assembly adapted to be disengaged allowing disassembly of saidupper member from said lower member.
 6. A coupler assembly as set forthin claim 1 wherein said mating end faces of said first and secondelectromagnets are protected against oxidation after assembly to saidlower and upper members respectively prior to coupler assembly.
 7. Acoupler assembly as set forth in claim 1 wherein said first securingmeans comprise at least one pivot pin at said pivot end of said lowermember, said second securing means comprise an elbow slot definingarcuate bearing surfaces at said pivot end of said upper memberproximate a lower surface of said lower member thereof, and said lowermember having said pivot pin positioned within said arcuate bearingsurfaces during assembly for rotation of said upper member with respectto said lower member prior to fastening of said first and secondfastening means together.
 8. A coupler assembly as set forth in claim 1wherein said lower member includes a means for mounting said lowermember to a panel having a plurality of pre-determined engaging surfacesformed on a panel comprising at least one fixed engaging member disposedon said lower member to engage one of said panel engaging surfaces andat least one movable engaging member disposed to engage another of saidpanel engaging surfaces, said movable engaging member positioned on asupport member operable between disengaged and engaged positions, saidengaged position determined by firm engagement with a respective one ofsaid panel engaging surfaces sufficient to adjust the position of saidlower member with respect to said panel, whereby said movable engagingmember positions both of said engaging members into engagement in theoperative position and disengagement in the inoperative position.
 9. Acoupler assembly as set forth in claim 8 wherein said movable engagingmember comprises a cam follower engaged by a cam operable by a handleformed on said cam.
 10. A coupler assembly as set forth in claim 9wherein said cam follower and cam include a sliding interlock to biasthe movable engaging member in a disengaged or engaged position.
 11. Acoupler assembly as set forth in claim 9 wherein said support memberincludes a plurality of engaging surfaces engageable with engagingsurfaces positioned on said cam whereby engagement of said surfacesfixedly positions said cam.
 12. A coupler assembly as set forth in claim10 wherein said cam includes bias means disposed to allow verticalmovement of said cam to disengage said respective engaging surfaces ofsaid support member and said cam.
 13. A coupler assembly as set forth inclaim 11 wherein said movable engaging member includes a projectionengageable with an actuating surface formed on said cam.
 14. A couplerassembly as set forth in claim 13 wherein said fixed and movableengaging members include respective locking surfaces which engagerespective said panel engaging surfaces.
 15. A coupler assembly as setforth in claim 14 wherein said locking surfaces of each of said fixedand movable engaging members comprise elephant feed having taperedsurfaces defining a largest portion of said engaging member at the lowerportion thereof.
 16. A coupler assembly as set forth in claim 13 whereinsaid cam positions said movable engaging member selectively in any oneof a plurality of engagement positions, said engaging member beingresponsive to any of said cam positions.
 17. A coupler assembly as setforth in claim 16 wherein said upper member includes portions engageablewith upper portions of said cam when said upper member is fully mated tosaid lower member, to assist in retaining said cam in said engagedposition, whereby said lower member remains assuredly mounted to saidpanel under vibration.
 18. A coupler assembly as set forth in claim 1wherein said lower member includes two said first electromagnets securedtherein spaced from each other, and said upper member includes two saidsecond electromagnets secured therein spaced from each other paired withand opposed from said two first electromagnets and each respectivelyinductively coupled by said circuit substrate, thereby defining a datacoupler having two said electromagnetic coils to enable both receivingand transmitting signals from and to said data bus.
 19. A couplerassembly as set forth in claim 18 wherein said two first electromagnetsare spring biased independently of each other.
 20. A coupler assembly asset forth in claim 18 wherein said dielectric body of said electromagnetinsert comprises deformable elastomeric material, and said lower memberincludes a rib disposed within a recess of said dielectric body andbetween said spaced apart first electromagnets, said rib including postsextending upwardly between respective paris of opposing ones of saidouter and central legs of said first electromagnets, whereby said firstelectromagnets are stabilized in a vertical orientation when subjectedto strain applied by said twisted pair cable.
 21. The coupler assemblyof claim 1, wherein said coupler assembly additionally comprises amounting means for mounting said first data coupler member to a thirdmember having a plurality of predetermined engaging surfaces formedthereon, said mounting means including at least one fixed engagingmember disposed on said first member to engage one of said engagingsurfaces of said other member; andat least one movable engaging memberdisposed to engage another of said engaging surfaces of said othermember; said movable engaging member being positioned on a supportmember operable between disengaged and engaged positions whereby saidmovable engaging member positions both of said engaging members intoengagement in the operable position and disengagement in the operableposition.
 22. The coupler assembly of claim 1, wherein said first datacoupler member includes a spring member disposed to provide axialpressure to said first electromagnet within said electromagnet insert,said spring member comprising a portion defining a transverse platformand a pair of adjacent spring arms extending from a common face of saidplatform in a common axial direction, each of said arms having an end inan adjacent relationship to a base of the other said spring arm, wherebysaid spring arms extend axially in the same direction from respectivesaid bases and transversely in opposed directions to free ends defininga pair of bearing portions disposed in a common plane to engage a commonsupport surface of said first data coupler member for generatingresistance to movement of said platform in said axial direction whensaid first electromagnet engages said second electromagnet upon matingof said first and second data coupler members.
 23. A system forprecisely aligning an upper member to a lower member of a data couplerduring mating, the data coupler being of the type having at least firstupper and lower electromagnets defining upon mating of the upper andlower coupler members at least a first electromagnet coil when abuttedand mated together at a mating interface about a pair of signalconductor wires of a twisted pair cable of a data bus for receiving ortransmitting signals in cooperation with a control unit electricallyconnected to the data coupler, comprising:first and second securingmeans at a first end of said upper and lower members, first and secondfastening means at a second end thereof, and first and second alignmentmeans along intermediate portions thereof between said first and secondends, said first and second securing means cooperable during initialstages of mating to define a pivot, said first and second fasteningmeans cooperable at final stages of mating to fasten together said upperand lower members about said signal conductor wires to define said atleast a first electromagnet coil therearound, and said first and secondalignment means cooperable during intermediate stages of mating forprecisely aligning said upper and lower members with each other; saidsecond securing means comprising transverse cylindrical pins at saidfirst end, and said first securing means comprising transverse elbowslots defined along and into a lower surface of said upper member havingvertical portions adapted to receive thereinto said transverse pins ofsaid lower member and further having horizontal portions extendingtoward said first end after said transverse pins have been received intosaid vertical slot portions, said horizontal portions having arcuatebearing surfaces facing said second end cooperable with surfaces of saidpins during pivoting; and said first alignment means comprising aprojection depending from said upper member toward said lower member,and said second alignment means comprising an aperture extending atleast into a top surface of said lower member adapted to receivethereinto said projection during intermediate stages of mating andhaving a shape and dimension corresponding closely with those of saidprojection, said projection having tapered surfaces at a leading endthereof and said aperture having tapered surfaces at the entrancethereof adapted to engage and incrementally adjust the position of saidupper member with respect to said lower member upon initial entry ofsaid projection into said aperture until said projection is coaxial withsaid aperture, said projection and said aperture being located adjacentsaid first and second electromagnets near said second end, andcenterlines of said projection and said aperture defining referencedatums for said upper and lower members respectively with respect towhich all other features of said upper and lower members are referenced,whereby alignment of said upper and lower members is determined by meansintegral therewith and essentially at a single point substantiallyspaced from the pivot point by said projection and aperture therebyenabling precise positioning during mating of all features of the uppermember with respect to corresponding features of the lower memberincluding the first and second electromagnets mounted thereinrespectively.
 24. An alignment system as set forth in claim 23 whereinsaid transverse pins of said lower member extend between flanges thereofwhereby said pins are substantially physically protected by portions ofsaid lower member against inadvertent contact and damage during handlingprior to assembly to said upper member, and said transverse slotscommunicate with side surfaces of said upper member along said verticaland horizontal portions thereof to accommodate said flanges.
 25. Analignment system as set forth in claim 23 wherein said first and secondfastening means are disengageable from each other after mating of saidupper and lower members, enabling removal of said upper member from saidlower member.
 26. A coupler assembly for coupling to a data bus systemhaving a twisted pair cable of signal conductor wires in a closed busloop comprising:at least one electromagnet core, each core defined by afirst and second electromagnet; a first data coupler member having saidfirst electromagnet within an electromagnet insert, said insertcomprising a dielectric member defining positions for a central leg ofsaid electromagnet with a mating face exposed in one direction along asurface, said dielectric member having a pair of wire-receiving channelsalong a wire-receiving face and coursing from a first common wire exitat one side to a second comon wire exit at an opposing side of saidmember defining pathways on each side of a central leg of saidelectromagnet, said wire receiving channels adapted to receive thereintofrom said wire-receiving face respective ones of wires of said twistedpair cable, said dielectric member having a periphery of saidwire-receiving face including a flexible lip to form a seal when engagedand compressed between opposed surfaces; a second data coupler memberdisposed for inducting power via the second electromagnet into saidelectromagnet core when mated with said first data coupler member, saidsecond data coupler member comprising an assembly of a circuitsubstrate, a top body member and a bottom body member, saidelectromagnet secured therewithin and having leg portions extendingthrough leg-receiving apertures of said circuit substrate and saidbottom body member to mating faces exposed for coupling withcorresponding mating faces of said first electromagnet, said top andbottom body members define a cavity along an interface therebetweenadapted to receive said circuit substrate, said circuit surface thereofhaving circuits inductively coupling to said at least one electromagnet;and said upper and lower body members having EMI/RFI shielding formed byplating at least on surfaces around said cavity, and engaging portionsof said top and bottom body members being conductively joined at saidinterface surrounding said cavity after said circuit substrate has beendisposed therewithin, said plating surrounding said circuit substratethereby protecting said electrical components from EMI/RFI interference.